Not Applicable.
This invention relates to casting shake-out units used to separate or remove sand from castings, and in particular, to a liner which forms the inner surface of the shake-out unit.
In the formation of a tumbling mill, such as a casting shake-out unit, rotary separator, media drum, material drier, lump crusher reclaimer, blending drum, sand screen, or the like, it is desirable to form the inner surface of the mill from segments. Thus, when individual segments wear out, they can be replaced easily and rapidly without the need to incur a significant amount of downtime or expense. An example of a shake-out unit having segmented inner liners is shown in U.S. Pat. No. 3,998,262 with is assigned to the same assignee as the present invention, and which is incorporated herein by reference. As set forth in that patent, the inner cylinder forming the inner surface of the unit is formed from a series of interconnected modular components. The operation of that unit, for its intended purpose, has performed highly satisfactorily. However, when the casting shake-out unit is operated continuously, the wear on the components causes the components or segments to gradually loosen. This requires a retightening of the entire formed inner surface. This retightening operation requires that the operator incur a significant amount of down time.
It is desirable for the mill to operate for a longer period before the segments begin to loosen and separate. In U.S. Pat. Nos. 4,502,808, 5,638,887, and 5,638,890, all of with are assigned to the same assignee as the present invention and incorporated herein by reference, the side edges of the segments are grooved to define a channel between neighboring segments. A pin or bar is inserted in the channel. In a completed lining, the bars tend to urge the segments apart, thus creating a tight fit in the completed cylindrical lining. These have also worked well. However, the pins and the interlocking of the liner segments can still be improved.
A tumbling unit such as a casting shake-out unit, rotary media drum, sand reclaimer or the like, is provided. The tumbling unit includes a cylindrical outer shell and a cylindrical inner shell. The inner liner is formed of a series of interfitting segments. The segments each have an inner surface, an outer surface, side edges, a front edge, a back edge, and a vane extending from the outer surface. The side edges of the segments have a groove formed therein which extends the length of said the edges. The grooves of neighboring segments define channel between the segments. To enable the segments to interfit, the segments include tongues on their segment front and back edges and cutouts in their corners. The tongues and cutouts are shaped and positioned to enable the segments to interfit with each other.
The pin or liner lock key is received in the channel to urge the neighboring segments apart to form a tight interfit among the segments in a row of the liner. The retaining pin has a body having side surfaces, a top surface, and a bottom surface. In one embodiment, a rib extends along each side surface which is shaped and sized to be received in the grooves of the neighboring segments. In a second embodiment, the rib is replaced with at least one dowel which extends through at least one opening in the pin body. The dowel extends from opposite sides of the pin, and the portions of the dowel extending from the pin are received in the grooves of the segments. An arm extends upwardly from the pin body top surface. When the pin is placed between two neighboring segments, it separates the segments. The pin arm conforms in shape and size to the side profile of the vane, and is positioned on the pin body to be in alignment with the vanes of the adjacent segments, to form a continuous vane on the liner. The pins have cutouts at opposite ends thereof which conform generally in size and shape to the profile of the segment cutouts.
In a second embodiment, the segments include a first and a second side, and a front and a back side. A first side flange extends along the first side; a second side flange extends along the second side; a front flange extends along the front side; and a back side flange extends along the back side. The flanges all have a width equal to approximately one-half the width of the segment body between the inner and outer surfaces of said segment body. The first side flange and bottom flange have a surface generally flush with one of the inner and outer surfaces of the segment; and the second side flange and the top flange have a surface generally flush with the other of the inner and outer surfaces of the segment. This gives the segment the appearance of two rectangles being placed on top of each other, with one rectangle being diagonally offset from the other rectangle.
In a third embodiment, the liner segments are provided with flanges extending along the side edges of the segments on the outer surface of the segments. The flanges include bolt holes which extend therethrough. When the segments are assembled together, the flanges of adjacent segments are adjacent each other, with their bolt holes aligned. A fastener, such as a bolt, pin, post, etc. is passed through the holes to retain the segments of a row of segments together. Holes are also placed in the bottom of the vane, at opposite ends of the vane. A pin, which is fixed to the outer cylinder, extends into the vane hole, to secure the segment to the outer cylinder.